Pioneering Public Welfare Innovations in Silicon Photonics and Nanocarbon Technology

Dr. Hung-Chih Lu, a trailblazer in silicon photonics and nanocarbon technology, continues to advance open-access innovation for the public good, breaking new ground across fields for over two decades. Amid the surging demand for AI computing in 2024, silicon photonics has become a focal point for research and development. Yet Dr. Lu embarked on his exploration of silicon photonics more than 20 years ago, dedicating himself to this technology in its nascent stages. Despite significant contributions, Dr. Lu's inventions have largely been shared without profit, remaining publicly available. In an era when information dissemination was limited, many did not know the original mind behind these technologies.

Foundational Work in Silicon Photonics (1999)

Dr. Lu began his silicon photonics research in 1999, focusing on photonic components. At that time, Taiwan's lack of advanced silicon dioxide chip processing facilities led him to use silicon wafer fabrication-an unconventional choice that paved the way for his subsequent patents in the United States. Unlike traditional semiconductor components, silicon photonics has distinct waveguide designs with broader waveguide widths, posing integration challenges with electronic components that continue today, particularly with respect to coupling and loss.

His early vision sought to combine electronic computation with photonic transmission, proposing that silicon photonics replace conventional interconnects to mitigate the high-frequency limitations from chip-to-pin bonding by implementing chip-to-chip photonic communication. This concept was central to his U.S. Patent No. US8406579 (see Figure 1), a core component that integrates wavelength division multiplexing and optical modulation, reducing the size of photonic elements while enhancing compatibility with electronics.

Figure 1: U.S. Patent No. US8406579, a core component enabling high-speed transmission between chips using silicon photonics.

Advances in High-Speed Interconnects with Silicon Photonic Superchips

With the growing demand for high-speed interconnectivity between multiple chips, silicon photonics has taken on even greater significance. Dr. Lu has since leveraged digital twin technology to create a silicon photonic superchip (Figure 2), a conceptual demonstration utilizing die shots of Intel CPUs and NVIDIA GPUs to illustrate the process of converting and transmitting signals between electronic and photonic domains.

Figure 2: Silicon photonic superchip model created by Dr. Hung-Chih Lu using digital twin technology.

In this model, two distinct DC light sources of varying wavelengths are coupled into a waveguide, using the core component from US8406579 to convert electronic signals from CPU and GPU into photonic signals, achieving wavelength multiplexing for transmission through a single fiber.

Explorations in Nanocarbon for Thermal Management

Due to funding limitations, Dr. Lu transitioned to consumer electronics after 2010, exploring thermal management technologies. While graphene's exceptional thermal and electrical conductivity gained widespread attention, practical performance only emerges under specific conditions: few-layer structures with minimal defects. Manufacturing challenges have restricted the commercial viability of graphene, with many "graphene" products containing minimal amounts of actual graphene.

In 2013, Dr. Lu discovered that graphene byproducts with high emissivity were ideal for LED cooling, leading to U.S. Patent No. US9170015. He developed a nanocarbon-based cooling and electrothermal technology, resulting in a passive liquid-cooled heat sink (Figure 3).

Figure 3: Dr. Lu's passive nanocarbon liquid cooling system.

In Figure 3, the left image shows the cooling unit's exterior, while the right illustrates the cross-sectional view. The heat sink adheres to the heat source, conducting thermal energy to a high-conductivity liquid. An internal structure maximizes liquid-contact surface area for heat exchange efficiency. The device utilizes a honeycomb structure coated in a nanocarbon thermal film to maximize radiant heat dissipation.

Given that thermal radiation power is proportional to temperature to the fourth power, Dr. Lu's discovery of nanocarbon electrothermal technology became especially valuable for high-temperature applications, providing superior radiative heat dissipation.

Dr. Lu further tested thermal radiation capacities across various nanocarbon materials (e.g., graphene, nanocarbon spheres, nanotubes, and diamond-like carbon) (Figure 4). Results indicated that untreated aluminum reached 96°C, while nanocarbon-coated aluminum maintained 86°C. Dr. Lu's custom nanocarbon mixture reached 81°C, underscoring nanocarbon's advantages in heat dissipation applications.

Figure 4: Thermal radiation testing of nanocarbon materials.

The Ideal and Ppersistence of Public Welfare Creation

Though his inventions have only recently begun to gain commercial traction, Dr. Lu's commitment to open, public-centered innovation continues to advance green technology for a sustainable future.

postal code: 328015, Taoyuan city, Taiwan

Dr. Lu's Studio
Devoted to the public welfare creation of ecology, technology and art.

This release was published on openPR.